1. Field of the Invention
This invention relates to an image forming apparatus comprising an image forming unit, such as a laser printer, for forming images on transfer materials, and an optional unit, such as a large-capacity paper feeding device integrally connected to the image forming unit.
2. Description of the Related Art
Hitherto, an image forming apparatus, such as a laser printer, was connected to optional units such as a paper feeding unit and a paper discharging unit, or to a paper inverting unit and a paper transfer unit. The optional units are placed in the same plane as the image forming apparatus, for example on the same table. Hence, a resultant system comprising the image forming apparatus and the optional units occupies a large area inevitably.